Function freeze_for_capture 

pub fn freeze_for_capture()

Pin the wall clock to CAPTURE_LOCAL_TIME in the local time zone for the rest of the process. The launcher calls this before it builds an app for --shots; never call it in a live session.

A capture draws every frame of the process from the thread that calls this, so it pins the process’s clock and not only its own thread’s. A test does not: it holds its own thread with [crate::time::testing].